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[v2] ata: sata_rcar: add gen[23] fallback compatibility strings

Message ID 1458871280-19330-1-git-send-email-horms+renesas@verge.net.au (mailing list archive)
State Superseded
Delegated to: Geert Uytterhoeven
Headers show

Commit Message

Simon Horman March 25, 2016, 2:01 a.m. UTC
Add fallback compatibility string for R-Car Gen 2 and 3.

In the case of Renesas R-Car hardware we know that there are generations of
SoCs, e.g. Gen 1 and 2. But beyond that its not clear what the relationship
between IP blocks might be. For example, I believe that r8a7790 is older
than r8a7791 but that doesn't imply that the latter is a descendant of the
former or vice versa.

We can, however, by examining the documentation and behaviour of the
hardware at run-time observe that the current driver implementation appears
to be compatible with the IP blocks on SoCs within a given generation.

For the above reasons and convenience when enabling new SoCs a
per-generation fallback compatibility string scheme being adopted for
drivers for Renesas SoCs.

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
---
Based on libata/for-next

v2
* As suggested by Geert Uytterhoeven:
  - Do not add R-Car Gen 1 compatibility string as the only SoC in
    that generation for which I have documentation indicating that
    SATA is present is the r8a7779 (H1). In particular it does not
    appear to be present on the r8a7798 (M1A) or E1.
---
 Documentation/devicetree/bindings/ata/sata_rcar.txt | 14 +++++++++++---
 drivers/ata/sata_rcar.c                             |  8 ++++++++
 2 files changed, 19 insertions(+), 3 deletions(-)

Comments

Geert Uytterhoeven March 25, 2016, 7:49 a.m. UTC | #1
On Fri, Mar 25, 2016 at 3:01 AM, Simon Horman
<horms+renesas@verge.net.au> wrote:
> Add fallback compatibility string for R-Car Gen 2 and 3.
>
> In the case of Renesas R-Car hardware we know that there are generations of
> SoCs, e.g. Gen 1 and 2. But beyond that its not clear what the relationship
> between IP blocks might be. For example, I believe that r8a7790 is older
> than r8a7791 but that doesn't imply that the latter is a descendant of the
> former or vice versa.
>
> We can, however, by examining the documentation and behaviour of the
> hardware at run-time observe that the current driver implementation appears
> to be compatible with the IP blocks on SoCs within a given generation.
>
> For the above reasons and convenience when enabling new SoCs a
> per-generation fallback compatibility string scheme being adopted for
> drivers for Renesas SoCs.
>
> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/ata/sata_rcar.txt b/Documentation/devicetree/bindings/ata/sata_rcar.txt
index 0764f9ab63dc..3431c22399fe 100644
--- a/Documentation/devicetree/bindings/ata/sata_rcar.txt
+++ b/Documentation/devicetree/bindings/ata/sata_rcar.txt
@@ -1,14 +1,22 @@ 
 * Renesas R-Car SATA
 
 Required properties:
-- compatible		: should contain one of the following:
+- compatible		: should contain one or more of the following:
 			  - "renesas,sata-r8a7779" for R-Car H1
-			    ("renesas,rcar-sata" is deprecated)
 			  - "renesas,sata-r8a7790-es1" for R-Car H2 ES1
 			  - "renesas,sata-r8a7790" for R-Car H2 other than ES1
 			  - "renesas,sata-r8a7791" for R-Car M2-W
 			  - "renesas,sata-r8a7793" for R-Car M2-N
 			  - "renesas,sata-r8a7795" for R-Car H3
+			  - "renesas,rcar-gen2-sata" for a generic R-Car Gen2 compatible device
+			  - "renesas,rcar-gen3-sata" for a generic R-Car Gen3 compatible device
+			  - "renesas,rcar-sata" is deprecated
+
+			  When compatible with the generic version, nodes
+			  must list the SoC-specific version corresponding
+			  to the platform first followed by the generic
+			  version.
+
 - reg			: address and length of the SATA registers;
 - interrupts		: must consist of one interrupt specifier.
 - clocks		: must contain a reference to the functional clock.
@@ -16,7 +24,7 @@  Required properties:
 Example:
 
 sata0: sata@ee300000 {
-	compatible = "renesas,sata-r8a7791";
+	compatible = "renesas,sata-r8a7791", "renesas,rcar-gen2-sata";
 	reg = <0 0xee300000 0 0x2000>;
 	interrupt-parent = <&gic>;
 	interrupts = <0 105 IRQ_TYPE_LEVEL_HIGH>;
diff --git a/drivers/ata/sata_rcar.c b/drivers/ata/sata_rcar.c
index f72d601e300a..07d7d922ee71 100644
--- a/drivers/ata/sata_rcar.c
+++ b/drivers/ata/sata_rcar.c
@@ -858,6 +858,14 @@  static struct of_device_id sata_rcar_match[] = {
 		.compatible = "renesas,sata-r8a7795",
 		.data = (void *)RCAR_GEN2_SATA
 	},
+	{
+		.compatible = "renesas,rcar-gen2-sata",
+		.data = (void *)RCAR_GEN2_SATA
+	},
+	{
+		.compatible = "renesas,rcar-gen3-sata",
+		.data = (void *)RCAR_GEN2_SATA
+	},
 	{ },
 };
 MODULE_DEVICE_TABLE(of, sata_rcar_match);